U.S. patent number 9,029,474 [Application Number 12/450,778] was granted by the patent office on 2015-05-12 for process for production of surface-modified polymer structures.
This patent grant is currently assigned to Kyushu University, Nissan Chemical Industries, Ltd.. The grantee listed for this patent is Kei-ichi Akabori, Hironori Atarashi, Toshihiko Nagamura, Keisuke Odoi, Masaaki Ozawa, Keiji Tanaka. Invention is credited to Kei-ichi Akabori, Hironori Atarashi, Toshihiko Nagamura, Keisuke Odoi, Masaaki Ozawa, Keiji Tanaka.
United States Patent |
9,029,474 |
Ozawa , et al. |
May 12, 2015 |
Process for production of surface-modified polymer structures
Abstract
The present invention relates to a process for producing a
polymer structure comprising: mixing and unifying a matrix polymer
made of a linear polymer and a highly-branched polymer having
hydrophilic functional groups at molecular ends and to form a
structure containing the matrix polymer and the highly-branched
polymer; and subjecting the obtained structure to either immersion
in water and/or a hydrophilic solvent or exposure to an atmosphere
of vapor of water and/or a hydrophilic solvent at a temperature
ranging from a temperature lower than Tg of the matrix polymer by
30.degree. C. to decomposition temperature of the matrix polymer;
wherein the hydrophilic functional groups at the molecular ends of
the highly-branched polymer are distributed in outermost surface of
the polymer structure at an enhanced density. The present invention
also relates to a process for producing a polymer structure in
which vinyl polymer chains are grafted to at least a part of the
hydrophilic functional groups.
Inventors: |
Ozawa; Masaaki (Funabashi,
JP), Odoi; Keisuke (Chiyoda-ku, JP),
Atarashi; Hironori (Fukuoka, JP), Akabori;
Kei-ichi (Fukuoka, JP), Nagamura; Toshihiko
(Fukuoka, JP), Tanaka; Keiji (Fukuoka,
JP) |
Applicant: |
Name |
City |
State |
Country |
Type |
Ozawa; Masaaki
Odoi; Keisuke
Atarashi; Hironori
Akabori; Kei-ichi
Nagamura; Toshihiko
Tanaka; Keiji |
Funabashi
Chiyoda-ku
Fukuoka
Fukuoka
Fukuoka
Fukuoka |
N/A
N/A
N/A
N/A
N/A
N/A |
JP
JP
JP
JP
JP
JP |
|
|
Assignee: |
Nissan Chemical Industries,
Ltd. (Tokyo, JP)
Kyushu University (Fukuoka-shi, JP)
|
Family
ID: |
39925731 |
Appl.
No.: |
12/450,778 |
Filed: |
April 23, 2008 |
PCT
Filed: |
April 23, 2008 |
PCT No.: |
PCT/JP2008/057874 |
371(c)(1),(2),(4) Date: |
December 15, 2009 |
PCT
Pub. No.: |
WO2008/133283 |
PCT
Pub. Date: |
November 06, 2008 |
Prior Publication Data
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|
|
|
Document
Identifier |
Publication Date |
|
US 20100120984 A1 |
May 13, 2010 |
|
Foreign Application Priority Data
|
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|
|
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Apr 25, 2007 [JP] |
|
|
2007-115883 |
|
Current U.S.
Class: |
525/72 |
Current CPC
Class: |
C08L
101/005 (20130101); C08J 7/12 (20130101) |
Current International
Class: |
C08L
51/00 (20060101); C08L 41/00 (20060101) |
Field of
Search: |
;525/77 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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1 854 814 |
|
Nov 2007 |
|
EP |
|
A-5-247198 |
|
Sep 1993 |
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JP |
|
A-11-263819 |
|
Sep 1999 |
|
JP |
|
A-2002-145971 |
|
May 2002 |
|
JP |
|
A-2003-522266 |
|
Jul 2003 |
|
JP |
|
A-2003-529658 |
|
Oct 2003 |
|
JP |
|
A-2004-346203 |
|
Dec 2004 |
|
JP |
|
A-2005-511875 |
|
Apr 2005 |
|
JP |
|
A-2005-511876 |
|
Apr 2005 |
|
JP |
|
A-2006-503947 |
|
Feb 2006 |
|
JP |
|
A-2006-113389 |
|
Apr 2006 |
|
JP |
|
A-2006-316169 |
|
Nov 2006 |
|
JP |
|
WO 2006/093050 |
|
Sep 2006 |
|
WO |
|
WO 2007/049608 |
|
May 2007 |
|
WO |
|
WO 2008/029806 |
|
Mar 2008 |
|
WO |
|
Other References
Walton and Mayes, Physical Review E, vol. 54, No. 3, pp. 28112815
(Sep. 1996). cited by examiner .
International Search Report issued in International Patent
Application No. PCT/JP2008/057874; mailed Aug. 5, 2008. cited by
applicant .
Ishizu et al., "Synthesis of hyperbranched polymers by
self-addition free radical vinyl polymerization of photo functional
styrene," Macromol Rapid Commun; vol. 21, No. 10, 2000; pp.
665-668. cited by applicant .
Ishizu et al., "Synthesis and characterization of hyperbranched
poly(ethyl methacrylate) by quasi-living radical polymerization of
photofunctional inimer," Polymer International; vol. 51, 2002; pp.
424-428. cited by applicant .
Atarashi et al., "Interfacial Segregation of Hyper-branched
Polystyrene in Mixtures of Linear Component," Transactions of the
Materials Research Society of Japan, vol. 32, No. 1, 2007, pp.
231-234. cited by applicant.
|
Primary Examiner: Mullis; Jeffrey
Attorney, Agent or Firm: Oliff PLC
Claims
The invention claimed is:
1. A process for producing a polymer structure in which a
hyperbranched polymer having hydrophilic functional groups at
molecular ends is contained in a matrix polymer made of a linear
polymer, the process comprising: mixing and unifying the matrix
polymer and the hyperbranched polymer to form a structure
containing the matrix polymer and the hyperbranched polymer; and
subjecting the obtained structure containing the matrix polymer and
the hyperbranched polymer to either immersion in water and/or a
hydrophilic solvent or exposure to an atmosphere of vapor of water
and/or a hydrophilic solvent at a temperature falling within a
range of a temperature lower than glass transition temperature of
the matrix polymer by 30.degree. C. to decomposition temperature of
the matrix polymer; wherein: the hyperbranched polymer is
concentrated around a surface and/or an interface of the polymer
structure; the hydrophilic functional groups at the molecular ends
of the hyperbranched polymer are distributed in an outermost
surface of the polymer structure at an enhanced density; and the
hyperbranched polymer is represented by Formula (1): ##STR00011##
where: R.sub.1 represents a hydrogen atom or a methyl group;
W.sub.1 and W.sub.2 represent a dithiocarbamate group; A.sub.1
represents a group represented by Formula (2) and/or Formula (3):
##STR00012## where: A.sub.2 represents a straight chain, branched
or cyclic alkylene group having 1to 30carbon atoms which optionally
contains an ether bond or an ester bond; and X.sub.1, X.sub.2,
X.sub.3 and X.sub.4 independently represent a hydrogen atom, an
alkyl group having 1to 20carbon atoms, an alkoxy group having 1to
20carbon atoms, a halogen atom, a nitro group, a hydroxyl group, an
amino group, a carboxyl group or a cyano group; and n is a number
of repeating unit structures and represents an integer of 5to
100,000.
2. The process for producing a polymer structure according to claim
1, wherein A.sub.1 represents a group represented by Formula (4):
##STR00013##
3. The process for producing a polymer structure according to claim
1, wherein A.sub.1 represents a group represented by Formula (5):
##STR00014## where m represents an integer of 2to 10.
4. The process for producing a polymer structure according to claim
1, wherein R.sub.1 is a hydrogen atom.
5. The process for producing a polymer structure according to claim
2, wherein R.sub.1 is a hydrogen atom.
6. The process for producing a polymer structure according to claim
1, wherein the matrix polymer is at least one type selected from
the group consisting of polystyrene, an AS resin, an ABS resin, an
MS resin, an acrylic resin, and a methacrylic resin.
7. The process for producing a polymer structure according to claim
6, wherein the matrix polymer is polystyrene.
8. The process for producing a polymer structure according to claim
1, wherein a treating time for the immersion or the exposure is
0.001to 100hours.
9. The process for producing a polymer structure according to claim
1, wherein the amount of the hyperbranched polymer mixed to the
matrix polymer is maximum 25% by mass to minimum 0.1% by mass,
based on the mass of the matrix polymer.
10. A polymer structure in which a hyperbranched polymer having
hydrophilic functional groups at molecular ends is contained in a
matrix polymer made of a linear polymer, wherein: the hyperbranched
polymer is concentrated around a surface and/or an interface of the
polymer structure; the hydrophilic functional groups at the
molecular ends of the hyperbranched polymer are distributed in an
outermost surface of the polymer structure at an enhanced density;
the hyperbranched polymer is represented by Formula (1):
##STR00015## where: R.sub.1 represents a hydrogen atom or a methyl
group; W.sub.1 and W.sub.2 represent a dithiocarbamate group;
A.sub.1 represents a group represented by Formula (2) and/or
Formula (3): ##STR00016## where: A.sub.2 represents a straight
chain, branched or cyclic alkylene group having 1to 30carbon atoms
which optionally contains an ether bond or an ester bond; and
X.sub.1, X.sub.2, X.sub.3 and X.sub.4 independently represent a
hydrogen atom, an alkyl group having 1to 20carbon atoms, an alkoxy
group having 1to 20carbon atoms, a halogen atom, a nitro group, a
hydroxyl group, an amino group, a carboxyl group or a cyano group;
and n is a number of repeating unit structures and represents an
integer of 5to 100,000.
11. The polymer structure according to claim 10, wherein A.sub.1
represents a group represented by Formula (4): ##STR00017##
12. The polymer structure according to claim 10, wherein A.sub.1
represents a group represented by Formula (5): ##STR00018## where m
represents an integer of 2to 10.
13. The polymer structure according to claim 10, wherein R.sub.1 is
a hydrogen atom.
14. The polymer structure according to claim 11, wherein R.sub.1 is
a hydrogen atom.
15. The polymer structure according to claim 10, wherein the matrix
polymer is at least one type selected from the group consisting of
polystyrene, an AS resin, an ABS resin, an MS resin, an acrylic
resin, and a methacrylic resin.
16. The polymer structure according to claim 15, wherein the matrix
polymer is polystyrene.
17. A process for producing a grafted polymer structure which is a
polymer structure in which a hyperbranced polymer having
hydrophilic functional groups at molecular ends is contained in a
matrix polymer made of a linear polymer, the process comprising:
mixing and unifying the matrix polymer and the hyperbranched
polymer to form a structure containing the matrix polymer and the
hyperbranced polymer; subjecting the obtained structure containing
the matrix polymer and the hyperbranched polymer to either
immersion in water and/or a hydrophilic solvent or exposure to an
atmosphere of vapor of water and/or a hydrophilic solvent at a
temperature falling within a range of a temperature lower than
glass transition temperature of the matrix polymer by 30.degree. C.
to decomposition temperature of the matrix polymer; and
graft-polymerizing vinyl polymer chains to the hydrophilic
functional groups positioned in an outermost surface of the treated
structure; wherein: the hyperbranched polymer is concentrated
around a surface and/or an interface of the polymer structure; the
hydrophilic functional groups at the molecular ends of the
hyperbranched polymer are distributed in the outermost surface of
the polymer structure at an enhanced density and the vinyl polymer
chains are grafted to at least a part of the hydrophilic functional
groups; and the hyperbranched polymer is represented by Formula
(1): ##STR00019## where: R.sub.1 represents a hydrogen atom or a
methyl group; W.sub.1 and W.sub.2 represent a dithiocarbamate
group; A.sub.1 represents a group represented by Formula (2) and/or
Formula (3): ##STR00020## where: A.sub.2 represents a straight
chain, branched or cyclic alkylene group having 1to 30carbon atoms
which optionally contains an ether bond or an ester bond; and
X.sub.1, X.sub.2, X.sub.3 and X.sub.4 independently represent a
hydrogen atom, an alkyl group having 1to 20carbon atoms, an alkoxy
group having 1to 20carbon atoms, a halogen atom, a nitro group, a
hydroxyl group, an amino group, a carboxyl group or a cyano group;
and n is a number of repeating unit structures and represents an
integer of 5to 100,000.
18. The process for producing a grafted polymer structure according
to claim 17, wherein A.sub.1 represents a group represented by
Formula (4): ##STR00021##
19. The process for producing a grafted polymer structure according
to claim 17, wherein A.sub.1 represents a group represented by
Formula (5): ##STR00022## where m represents an integer of 2to
10.
20. The process for producing a grafted polymer structure according
to claim 17, wherein R.sub.1 is a hydrogen atom.
21. The process for producing a grafted polymer structure according
to claim 18, wherein R.sub.1 is a hydrogen atom.
22. The process for producing a grafted polymer structure according
claim 17, wherein the matrix polymer is at least one type selected
from the group consisting of polystyrene, an AS resin, an ABS
resin, an MS resin, an acrylic resin, and a methacrylic resin.
23. The process for producing a grafted polymer structure according
to claim 22, wherein the matrix polymer is polystyrene.
24. The process for producing a grafted polymer structure according
to claim 17, wherein a treating time for the immersion or the
exposure is 0.001to 100hours.
25. The process for producing a grafted polymer structure according
to claim 17, wherein the amount of the hyperbranced polymer mixed
to the matrix polymer is maximum 25% by mass to minimum 0.1% by
mass, based on the mass of the matrix polymer.
26. The process for producing a grafted polymer structure according
to claim 17, wherein each of the vinyl polymer chains is grafted by
a living radical polymerization.
27. The process for producing a grafted polymer structure according
to claim 26, wherein a polymerization time for the living radical
polymerization is 0.01to 100hours.
28. The process for producing a grafted polymer structure according
to claim 26, wherein a polymerization time for the living radical
polymerization is 0.1to 100hours.
29. The process for producing a grafted polymer structure according
to claim 26, wherein a polymerization temperature for the living
radical polymerization is 0to 200.degree. C.
30. The process for producing a grafted polymer structure according
to claim 17, wherein each of the vinyl polymer chains is formed
from acrylamides or methacrylamides.
31. A grafted polymer structure which is a polymer structure in
which a hyperbranched polymer having hydrophilic functional groups
at molecular ends is contained in a matrix polymer made of a linear
polymer, wherein: the hyperbranched polymer is concentrated around
a surface and/or an interface of the polymer structure; the
hydrophilic functional groups at the molecular ends of the
hyperbranched polymer are distributed in an outermost surface of
the polymer structure at an enhanced density; vinyl polymer chains
are grafted to at least a part of the hydrophilic functional
groups; and the hyperbranched polymer is represented by Formula
(1): ##STR00023## where: R.sub.1 represents a hydrogen atom or a
methyl group; W.sub.1 and W.sub.2 represent a dithiocarbamate
group; A.sub.1 represents a group represented by Formula (2) and/or
Formula (3): ##STR00024## where: A.sub.2 represents a straight
chain, branched or cyclic alkylene group having 1to 30carbon atoms
which optionally contains an ether bond or an ester bond; and
X.sub.1, X.sub.2, X.sub.3 and X.sub.4 independently represent a
hydrogen atom, an alkyl group having 1to 20carbon atoms, an alkoxy
group having 1to 20carbon atoms, a halogen atom, a nitro group, a
hydroxyl group, an amino group, a carboxyl group or a cyano group);
and n is a number of repeating unit structures and represents an
integer of 5to 100,000.
32. The grafted polymer structure according to claim 31, wherein
A.sub.1 represents a group represented by Formula (4):
##STR00025##
33. The grafted polymer structure according to claim 31, wherein
A.sub.1 represents a group represented by Formula (5): ##STR00026##
(where m represents an integer of 2to 10).
34. The grafted polymer structure according to claim 31, wherein
R.sub.1 is a hydrogen atom.
35. The grafted polymer structure according to claim 32, wherein
R.sub.1 is a hydrogen atom.
36. The grafted polymer structure according to claim 31, wherein
the matrix polymer is at least one type selected from the group
consisting of polystyrene, an AS resin, an ABS resin, an MS resin,
an acrylic resin, and a methacrylic resin.
37. The grafted polymer structure according to claim 36, wherein
the matrix polymer is polystyrene.
38. The grafted polymer structure according to claim 31, wherein
each of the vinyl polymer chains is formed from acrylamides or
methacrylamides.
39. The grafted polymer structure according to claim 31, wherein
each of the vinyl polymer chains is grafted by a living radical
polymerization.
Description
TECHNICAL FIELD
The present invention relates to a novel technology applicable to a
surface modification of a polymer. The surface-modified polymer
structure or grafted polymer structure according to the present
invention has such characteristics as capability of imparting wear
resistance, lubricity, chemical resistance, anticorrosion property,
antistatic property, adhesion/cohesion, light antireflection
property, light opacity and etching resistance to the surface of
the structure and capability of controlling
hydrophilicity/lipophilicity, a light reflectance, a light
extraction efficiency, alkali developing property, surface hardness
and the like. Therefore, these structures can be suitably utilized
as: a molding material such as electric/electronic parts,
automobile parts, optical controlling parts, parts for printing
apparatuses, film/sheet materials, fiber materials and
medicine/diagnose materials; a thin film material such as
semiconductor materials, display materials and materials for
electronic devices; and gradient materials in which refractive
index, dielectric constant, thermal expansion coefficient, magnetic
property and the like are controlled.
BACKGROUND ART
Recently, polymer materials are increasingly utilized in various
fields. Following such a tendency, corresponding to each need,
besides properties of a polymer as a matrix, surface
characteristics of the polymer are becoming important. For example,
characteristics such as adhesion, cohesion, nonadhesiveness,
antistatic properties, water-/oil-repellent properties,
hydrophilicity, sliding properties and biocompatibility are
required for the surface of a polymer.
Conventionally, various polymer surface modifying methods for
imparting the above characteristics to the surface of a polymer are
known (for example, Non-patent Document 1). For example, there is
known a method for taking a physical measure represented by the
irradiation of various energy rays, however, it requires cumbersome
operations to become an expensive method (for example, Patent
Document 1 and Patent Document 2).
The same applicants as those of the present invention disclose that
as a polymer surface modifying method, by such a simple operation
as mixing a highly-branched polymer to a matrix polymer made of a
linear polymer, a highly-branched polymer can be concentrated on
the surface and/or the interface of the matrix polymer (for
example, Non-patent Document 2).
However, in this report, there is no description on distributing
hydrophilic functional groups at the molecular ends of the
highly-branched polymer in the outermost surface of a polymer
structure at an enhanced density, and there is not indicated an
action effect by this distribution.
In addition, for the purpose of modifying a polymer surface, there
is known a method of adding or applying a highly-branched polymer,
however, there is no description on distributing functional groups
at the molecular ends of the highly-branched polymer in the
outermost surface of a polymer structure at an enhanced density
(for example, Patent Document 7, Patent Document 8 and Patent
Document 9).
In addition, as one of polymer surface modifying methods, there is
known a method of grafting a polymer chain through a polymerization
initiating group formed in the surface of a solid (for example,
Patent Document 3, Patent Document 4 and Patent Document 5). This
surface modifying method by a surface graft polymerization can
impart diverse surface characteristics by varying the type of a
monomer to be polymerized. However, in these documents, a method of
fixing a polymerization initiating group to the surface requires a
cumbersome step such as the Langmuir-Blodgett method (LB method)
and a chemisorption method, so that there has been desired a method
capable of performing a polymer surface modification for a wider
surface area by a simple step. In addition, a surface modifying
method by fixing a dithiocarbamate group which is a
photopolymerization initiating group to the polymer surface by the
LB method or a chemisorption method to graft-polymerize the
polymer, is publicly-known (for example, Patent Document 6).
However, in these documents, there is no description on technical
methods and means of distributing hydrophilic functional groups at
the molecular ends of a highly-branched polymer contained in a
polymer structure and concentrated on the surface and/or the
interface of the polymer structure in the outermost surface of the
polymer structure at an enhanced density, so as to further graft
polymer chains to the hydrophilic functional groups distributed in
the outermost surface at an enhanced density. Also, there is no
indication of advantageous effects obtained by these technical
methods and means.
In addition, as a highly-branched polymer having a dithiocarbamate
group at the molecular ends, there are known styrene-based
hyperbranched polymers and acryl-based hyperbranched polymers (for
example, Non-patent Document 3 and Non-patent Document 4).
Non-patent Document 1: Edited by Teruo Tsunoda, Kobunshi no
Hyomenkaishitsu to Oyo (Surface Modification of Polymer and
Application Thereof), published by CMC Publishing Co., Ltd. in
June, 2001 Non-patent Document 2: Transactions of the Materials
Research Society of Japan Vol. 32(1), p.p. 231 (2007) Non-patent
Document 3: Macromol. Rapid Commun. Vol. 21, p.p. 665 to 668 (2000)
Non-patent Document 4: Polymer International Vol. 51, p.p. 424 to
428 (2002) Patent Document 1: JP-T-2005-511875 Patent Document 2:
JP-T-2005-511876 Patent Document 3: Japanese Patent Application
Publication No. JP-A-11-263819 Patent Document 4: JP-T-2002-145971
Patent Document 5: Japanese Patent Application Publication No.
JP-A-2006-316169 Patent Document 6: Japanese Patent Application
Publication No. JP-A-2006-113389 Patent Document 7:
JP-T-2003-522266 Patent Document 8: JP-T-2003-529658 Patent
Document 9: JP-T-2006-503947
DISCLOSURE OF THE INVENTION
[Problems to be Solved by the Invention]
In order to solve the problems described above, it is an object of
the present invention to provide a novel and simple general-purpose
technology capable of modifying the surface of a polymer structure,
in which highly-branched polymers having hydrophilic functional
groups at the molecular ends are contained in a matrix polymer made
of a linear polymer, by distributing hydrophilic functional groups
at the molecular ends of the highly-branched polymer in the
outermost surface of the polymer structure at an enhanced density,
and further, by a surface graft polymerization.
Means for Solving the Problems
As a result of assiduous research intended to achieve the above
object, the present inventors have found that by subjecting a
polymer structure containing a matrix polymer made of a linear
polymer and a highly-branched polymer to a treatment at a specific
temperature and in a specific atmosphere, it is possible to
distribute hydrophilic functional groups at the molecular ends of
the highly-branched polymer in the outermost surface of the polymer
structure at an enhanced density, and that by graft-polymerizing
the outermost surface of the polymer structure, it is possible to
modify the surface of the polymer structure, then the present
inventors have completed the present invention.
That is, the present invention is, according to a first aspect, a
process for producing a polymer structure in which a
highly-branched polymer having hydrophilic functional groups at the
molecular ends is contained in a matrix polymer made of a linear
polymer includes: mixing and unifying the matrix polymer and the
highly-branched polymer to form a structure containing the matrix
polymer and the highly-branched polymer; and subjecting the
obtained structure containing the matrix polymer and the
highly-branched polymer to either immersion in water and/or a
hydrophilic solvent or exposure to an atmosphere of vapor of water
and/or a hydrophilic solvent at a temperature falling within the
range of a temperature lower than the glass transition temperature
of the matrix polymer by 30.degree. C. to the decomposition
temperature of the matrix polymer; in which the hydrophilic
functional groups at the molecular ends of the highly-branched
polymer are distributed in the outermost surface of the polymer
structure at an enhanced density;
according to a second aspect, the process for producing a polymer
structure according to the first aspect, characterized in that the
highly-branched polymer is at least one type selected from a group
consisting of a dendritic polymer, a comb polymer and a
hyperbranched polymer;
according to a third aspect, the process for producing a polymer
structure according to the second aspect, characterized in that the
hyperbranched polymer is a hyperbranched polymer represented by
Formula (1):
##STR00001## (where R.sub.1 represents a hydrogen atom or a methyl
group; W.sub.1 and W.sub.2 independently represent a thiol group, a
halogen atom, an amino group or a dithiocarbamate group; A.sub.1
represents a group represented by Formula (2) and/or Formula
(3):
##STR00002## (where A.sub.2 represents a straight chain, branched
or cyclic alkylene group having 1 to 30 carbon atom(s) which may
contain an ether bond or an ester bond; and X.sub.1, X.sub.2,
X.sub.3 and X.sub.4 independently represent a hydrogen atom, an
alkyl group having 1 to 20 carbon atom(s), an alkoxy group having 1
to 20 carbon atom(s), a halogen atom, a nitro group, a hydroxyl
group, an amino group, a carboxyl group or a cyano group); and n is
a number of repeating unit structures and represents an integer of
2 to 100,000);
according to a fourth aspect, the process for producing a polymer
structure according to the third aspect, in which A.sub.1
represents a group represented by Formula (4):
##STR00003##
according to a fifth aspect, the process for producing a polymer
structure according to the third aspect, in which A.sub.1
represents a group represented by Formula (5):
##STR00004## (where m represents an integer of 2 to 10);
according to a sixth aspect, the process for producing a polymer
structure according to any one of the third aspect to the fifth
aspect, in which each of W.sub.1 and W.sub.2 is a dithiocarbamate
group;
according to a seventh aspect, the process for producing a polymer
structure according to any one of the third aspect to the fifth
aspect, in which R.sub.1 is a hydrogen atom;
according to an eighth aspect, the process for producing a polymer
structure according to the fourth aspect, in which each of W.sub.1
and W.sub.2 is a dithiocarbamate group and R.sub.1 is a hydrogen
atom;
according to a ninth aspect, the process for producing a polymer
structure according to any one of the third aspect to the eighth
aspect, in which the matrix polymer is at least one type selected
from a group consisting of polystyrene, an AS resin, an ABS resin,
an MS resin, an acrylic resin and a methacrylic resin;
according to a tenth aspect, the process for producing a polymer
structure according to the ninth aspect, in which the matrix
polymer is polystyrene;
according to an eleventh aspect, the process for producing a
polymer structure according to the first aspect, in which a
treating time for the immersion or the exposure is 0.001 to 100
hours;
according to a twelfth aspect, the process for producing a polymer
structure according to the first aspect, in which the amount of the
highly-branched polymer mixed to the matrix polymer is maximum 25%
by mass to minimum 0.1% by mass, based on the mass of the matrix
polymer;
according to a thirteenth aspect, a polymer structure in which a
highly-branched polymer having hydrophilic functional groups at the
molecular ends is contained in a matrix polymer made of a linear
polymer, characterized in that the highly-branched polymer is
concentrated around the surface and/or the interface of the polymer
structure and the hydrophilic functional groups at the molecular
ends of the highly-branched polymer are distributed in the
outermost surface of the polymer structure at an enhanced
density;
according to a fourteenth aspect, the polymer structure according
to the thirteenth aspect, characterized in that the highly-branched
polymer is at least one type selected from a group consisting of a
dendritic polymer, a comb polymer and a hyperbranched polymer;
according to a fifteenth aspect, the polymer structure according to
the fourteenth aspect, characterized in that the hyperbranched
polymer is a hyperbranched polymer represented by Formula (1);
according to a sixteenth aspect, the polymer structure according to
the fifteenth aspect, in which A.sub.1 represents a group
represented by Formula (4);
according to a seventeenth aspect, the polymer structure according
to the fifteenth aspect, in which A.sub.1 represents a group
represented by Formula (5);
according to an eighteenth aspect, the polymer structure according
to any one of the fifteenth aspect to the seventeenth aspect, in
which each of W.sub.1 and W.sub.2 is a dithiocarbamate group;
according to a nineteenth aspect, the polymer structure according
to any one of the fifteenth aspect to the seventeenth aspect, in
which R.sub.1 is a hydrogen atom;
according to a twentieth aspect, the polymer structure according to
the sixteenth aspect, in which each of W.sub.1 and W.sub.2 is a
dithiocarbamate group and R.sub.1 is a hydrogen atom;
according to a twenty-first aspect, the polymer structure according
to any one of the fifteenth aspect to the twentieth aspect, in
which the matrix polymer is at least one type selected from a group
consisting of polystyrene, an AS resin, an ABS resin, an MS resin,
an acrylic resin and a methacrylic resin;
according to a twenty-second aspect, the polymer structure
according to the twenty-first aspect, in which the matrix polymer
is polystyrene;
according to a twenty-third aspect, a process for producing a
grafted polymer structure which is a polymer structure in which a
highly-branched polymer having hydrophilic functional groups at the
molecular ends is contained in a matrix polymer made of a linear
polymer includes: mixing and unifying the matrix polymer and the
highly-branched polymer to form a structure containing the matrix
polymer and the highly-branched polymer; subjecting the obtained
structure containing the matrix polymer and the highly-branched
polymer to either immersion in water and/or a hydrophilic solvent
or exposure to an atmosphere of vapor of water and/or a hydrophilic
solvent at a temperature falling within the range of a temperature
lower than the glass transition temperature of the matrix polymer
by 30.degree. C. to the decomposition temperature of the matrix
polymer; and graft-polymerizing vinyl polymer chains to hydrophilic
functional groups positioned in the outermost surface of the
treated structure; in which the hydrophilic functional groups at
the molecular ends of the highly-branched polymer are distributed
in the outermost surface of the polymer structure at an enhanced
density and the vinyl polymer chains are grafted to at least a part
of the hydrophilic functional groups;
according to a twenty-fourth aspect, the process for producing a
grafted polymer structure according to the twenty-third aspect,
characterized in that the highly-branched polymer is at least one
type selected from a group consisting of a dendritic polymer, a
comb polymer and a hyperbranched polymer;
according to a twenty-fifth aspect, the process for producing a
grafted polymer structure according to the twenty-fourth aspect,
characterized in that the hyperbranched polymer is a hyperbranched
polymer represented by Formula (1);
according to a twenty-sixth aspect, the process for producing a
grafted polymer structure according to the twenty-fifth aspect, in
which A.sub.1 represents a group represented by Formula (4);
according to a twenty-seventh aspect, the process for producing a
grafted polymer structure according to the twenty-fifth aspect, in
which A.sub.1 represents a group represented by Formula (5);
according to a twenty-eighth aspect, the process for producing a
grafted polymer structure according to any one of the twenty-fifth
aspect to the twenty seventh aspect, in which each of W.sub.1 and
W.sub.2 is a dithiocarbamate group;
according to a twenty-ninth aspect, the process for producing a
grafted polymer structure according to any one of the twenty-fifth
aspect to the twenty-seventh aspect, in which R.sub.1 is a hydrogen
atom;
according to a thirtieth aspect, the process for producing a
grafted polymer structure according to the twenty-sixth aspect, in
which each of W.sub.1 and W.sub.2 is a dithiocarbamate group and
R.sub.1 is a hydrogen atom;
according to a thirty-first aspect, the process for producing a
grafted polymer structure according to any one of the twenty-fifth
aspect to the thirtieth aspect, in which the matrix polymer is at
least one type selected from a group consisting of polystyrene, an
AS resin, an ABS resin, an MS resin, an acrylic resin and a
methacrylic resin;
according to a thirty-second aspect, the process for producing a
grafted polymer structure according to the thirty-first aspect, in
which the matrix polymer is polystyrene;
according to a thirty-third aspect, the process for producing a
grafted polymer structure according to the twenty-third aspect, in
which a treating time for the immersion or the exposure is 0.001 to
100 hours;
according to a thirty-fourth aspect, the process for producing a
grafted polymer structure according to the twenty-third aspect, in
which the amount of the highly-branched polymer mixed to the matrix
polymer is maximum 25% by mass to minimum 0.1% by mass, based on
the mass of the matrix polymer;
according to a thirty-fifth aspect, the process for producing a
grafted polymer structure according to the twenty-third aspect,
characterized in that each of the vinyl polymer chains is grafted
by a living radical polymerization;
according to a thirty-sixth aspect, the process for producing a
grafted polymer structure according to the thirty-fifth aspect, in
which a polymerization time for the living radical polymerization
is 0.01 to 100 hours;
according to a thirty-seventh aspect, the process for producing a
grafted polymer structure according to the thirty-fifth aspect, in
which a polymerization time for the living radical polymerization
is 0.1 to 100 hours;
according to a thirty-eighth aspect, the process for producing a
grafted polymer structure according to the thirty-fifth aspect, in
which a polymerization temperature for the living radical
polymerization is 0 to 200.degree. C.;
according to a thirty-ninth aspect, the process for producing a
grafted polymer structure according to the twenty-fifth aspect,
characterized in that each of the vinyl polymer chains is formed
from acrylamides or methacrylamides;
according to a fortieth aspect, a grafted polymer structure which
is a polymer structure in which a highly-branched polymer having
hydrophilic functional groups at the molecular ends is contained in
a matrix polymer made of a linear polymer, characterized in that:
the highly-branched polymer is concentrated around the surface
and/or the interface of the polymer structure; the hydrophilic
functional groups at the molecular ends of the highly-branched
polymer are distributed in the outermost surface of the polymer
structure at an enhanced density; and vinyl polymer chains are
grafted to at least a part of the hydrophilic functional
groups;
according to a forty-first aspect, the grafted polymer structure
according to the fortieth aspect, characterized in that the
highly-branched polymer is at least one type selected from a group
consisting of a dendritic polymer, a comb polymer and a
hyperbranched polymer;
according to a forty-second aspect, the grafted polymer structure
according to the forty-first aspect, characterized in that the
hyperbranched polymer is a hyperbranched polymer represented by
Formula (1);
according to a forty-third aspect, the grafted polymer structure
according to the forty-second aspect, in which A.sub.1 represents a
group represented by Formula (4);
according to a forty-fourth aspect, the grafted polymer structure
according to the forty-second aspect, in which A.sub.1 represents a
group represented by Formula (5);
according to a forty-fifth aspect, the grafted polymer structure
according to any one of the forty-second aspect to the forty-fourth
aspect, in which each of W.sub.1 and W.sub.2 is a dithiocarbamate
group;
according to a forty-sixth aspect, the grafted polymer structure
according to any one of the forty-second aspect to the forty-fourth
aspect, in which R.sub.1 is a hydrogen atom;
according to a forty-seventh aspect, the grafted polymer structure
according to the forty-third aspect, in which each of W.sub.1 and
W.sub.2 is a dithiocarbamate group and R.sub.1 is a hydrogen
atom;
according to a forty-eighth aspect, the grafted polymer structure
according to any one of the forty-second aspect to the
forty-seventh aspect, in which the matrix polymer is at least one
type selected from a group consisting of polystyrene, an AS resin,
an ABS resin, an MS resin, an acrylic resin and a methacrylic
resin;
according to a forty-ninth aspect, the grafted polymer structure
according to the forty-eighth aspect, in which the matrix polymer
is polystyrene;
according to a fiftieth aspect, the grafted polymer structure
according to the fortieth aspect, characterized in that each of the
vinyl polymer chains is formed from acrylamides or methacrylamides;
and
according to a fifty-first aspect, the grafted polymer structure
according to the fortieth aspect, characterized in that each of the
vinyl polymer chains is grafted by a living radical
polymerization.
Effects of the Invention
According to the present invention, only by subjecting a polymer
structure in which a matrix polymer made of a linear polymer and a
highly-branched polymer having hydrophilic functional groups at the
molecular ends are mixed to a treatment under simple conditions,
the hydrophilic functional groups at the molecular ends of the
highly-branched polymer are distributed in the outermost surface of
the structure at an enhanced density, and further if necessary, by
grafting desired polymer chains to the hydrophilic functional
groups, there can be obtained a polymer structure in which various
surface characteristics are modified according to a need for the
matrix polymer.
Particularly, when as the highly-branched polymer, a hyperbranched
polymer having a dithiocarbamate group acting as a
photopolymerization initiator at the molecular end is used, there
can be obtained a grafted polymer structure surface-modified with
vinyl polymers such as acrylamides and methacrylamides by a surface
graft (living radical) polymerization.
BEST MODES FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described more in
detail.
The process for producing a polymer structure according to the
present invention in which hydrophilic functional groups at the
molecular ends of a highly-branched polymer are distributed in the
outermost surface of the polymer structure at an enhanced density
is a process including: mixing and unifying a matrix polymer made
of a linear polymer and a highly-branched polymer having
hydrophilic functional groups at the molecular ends to form a
structure containing the matrix polymer and the highly-branched
polymer; and subjecting the obtained structure containing the
matrix polymer and the highly-branched polymer to either immersion
in water and/or a hydrophilic solvent or exposure to an atmosphere
of vapor of water and/or a hydrophilic solvent at a temperature
falling within the range of a temperature lower than the glass
transition temperature of the matrix polymer by 30.degree. C. to
the decomposition temperature of the matrix polymer
As the matrix polymer made of a linear polymer used in the process
for the production according to the present invention, various
types of polymers can be used. Examples of the polymer used include
vinyl chloride resins, vinylidene chloride resins, vinyl acetate
resins, polyvinyl alcohol, polyvinyl acetal, polystyrene, AS resins
(copolymer compounds of acrylonitrile and styrene), ABS resins
(copolymer compounds of acrylonitrile, butadiene and styrene), MS
resins (copolymer compounds of methyl methacrylate and styrene),
acrylic resins, methacrylic resins, polyethylene, polypropylene,
fluorine resins, polyamide, polyacetal, polycarbonate, modified
polyphenylene ether, polysulfone, polyester, polyphenylene sulfide,
liquid crystal plastics, polyimide, polyurethane, silicone resins,
diaryl phthalate resins, polybutadiene, polyisoprene, natural
rubbers, chloroprene rubbers, ethylene-propylene rubbers,
nitrilebutadiene rubbers, fluorine rubbers and butyl rubbers, and
also includes copolymers of these polymers. Needless to say,
however, examples of the polymer used are not limited to these
examples.
The highly-branched polymer having hydrophilic functional groups at
the molecular ends used in the process for the production according
to the present invention is characterized by having hydrophilic
functional groups at the end groups of the highly-branched polymer.
It is preferred that all of the end groups are hydrophilic
functional groups, however, only a part of the end groups may be
hydrophilic functional groups. Examples of the hydrophilic
functional groups include a hydroxyl group, a carboxyl group, an
amino group, a thiol group, a halogen atom, an epoxy group and a
dithiocarbamate group, and these groups may be mixed as a
combination of two or more types thereof.
The highly-branched polymer is a polymer exhibiting a molecule
structure in which the molecule spreads not in a single direction,
but in a plurality of directions, and generally refers to a polymer
known as a multi-branched polymer, that is, a dendritic polymer, a
comb polymer or a hyperbranched polymer. These polymers may be used
in combination of two or more types thereof.
Here, the dendritic polymer (dendritic macromolecule) is a
sphere-shaped macromolecule generally known as a dendrimer in which
the molecules radiate. In addition, the comb polymer is a polymer
composed of a comb-shaped molecular structure as a whole in which
side groups (side chains) are relatively regularly bonded to the
backbone. Further, the hyperbranched polymer is a polymer composed
of a highly branched structure and most of the hyperbranched
polymer is synthesized generally by a self-condensation of an
AB.sub.2-type monomer. However, the principle of the present
invention is not limited to the above multi-branched polymers and
as is apparent from the below descriptions, the present invention
can be conducted using any type of macromolecular compounds so long
as the macromolecular compounds have branched parts and the
molecules spreading in a plurality of directions, with the proviso
that there exists a variation of the effect.
The hyperbranched polymer generally refers to a compound produced
by polymerizing an AB.sub.x-type compound having in one molecule
thereof, both one A functional group and two or more B functional
groups capable of being reacted with the A functional group such as
AB.sub.2 and AB.sub.3, or a compound combining one polymerizing
site and one initiator which is referred to as AB*-type, utilizing
condensation, addition or insertion reaction, and is a highly
branched polymer. The AB*-type molecule is a compound in which an A
functional group corresponding to a polymerizing site and a B*
functional group acting as an initiator are reacted with each other
and after the reaction, the A functional group disappears, however,
B* maintains the reactivity as B* by an elimination or addition
even after the reaction. Here, examples of the AB.sub.2-type
include a combination of a carboxyl group as the A functional group
and an amino group as the B functional group and in this case, the
produced hyperbranched polymer becomes a hyperbranched polyamide.
Examples of the AB*-type include a combination of a styrenic double
bond as the A functional group and a dithiocarbamate group as the
B* functional group and in this case, the produced hyperbranched
polymer becomes a hyperbranched polystyrene. Examples of the
AB*-type also include a combination of a methacrylic double bond as
the A functional group and a dithiocarbamate group as the B*
functional group and in this case, the produced hyperbranched
polymer becomes a hyperbranched polymethacrylate.
Preferred examples of the hyperbranched polymer having hydrophilic
functional groups at the molecular ends used in the process for the
production according to the present invention include polymers
represented by Formula (1).
In Formula (1), as W.sub.1 and W.sub.2 representing hydrophilic
functional groups at the molecular ends, a dithiocarbamate group is
preferred taking into consideration the fact that a dithiocarbamate
group can be living radical-polymerized.
Examples of the hyperbranched polymer having dithiocarbamate groups
at the molecular ends include hyperbranched polymers represented by
Formulae (6) to (8) and hyperbranched polymers constituted by units
represented by Formulae (9) to (11), but are not limited
thereto.
The hyperbranched polymers represented by Formulae (6) to (8) and
the hyperbranched polymers constituted by units represented by
Formulae (9) to (11) are available from Nissan Chemical Industries,
Ltd. under a trade name of OPTBEADS Series.
##STR00005## (where R.sub.1, A.sub.1 and n represent the same as
those defined in Formula (1); and DC represents a dithiocarbamate
group).
A hyperbranched polymer by represented Formula (6) in which A.sub.1
represents a group represented by Formula (4) and/or Formula (5) is
preferred.
In addition, as the hyperbranched polymer having dithiocarbamate
groups at the molecular ends, copolymerization-type hyperbranched
polymers represented by Formula (7) and Formula (8) can also be
used.
##STR00006## (where DC represents a dithiocarbamate group; and n
represents the number of repeating unit structures and is an
integer of 2 to 100,000).
##STR00007## (where DC represents a dithiocarbamate group; n
represents the number of repeating unit structures and is an
integer of 2 to 100,000; and R.sub.2 and R.sub.3 individually
represent a hydrogen atom or a metal atom).
Further, as the hyperbranched polymer having dithiocarbamate groups
at the molecular ends, there can also be used a hyperbranched
polymer having a structural formula represented by Formula (9) as
the polymerization initiating site, a repeating unit in a straight
chain structure represented by Formula (10) and a repeating unit in
a branched structure represented by Formula (11), where the total
number of the repeating units in a straight chain structure
represented by Formula (10) is an integer of 1 to 100,000 and the
total number of the repeating units in a branched structure
represented by Formula (11) is an integer of 2 to 100,000.
##STR00008## (in Formulae (9) to (11), R.sub.4 represents a
hydrogen atom or a methyl group; R.sub.5 represents a hydrogen
atom, a straight chain or branched hydroxyalkyl group having 1 to
20 carbon atom(s) or a straight chain or branched alkyl group
having 3 to 20 carbon atoms and containing an epoxy group; and
A.sub.3 represents a structure represented by Formula (12) or
Formula (13):
##STR00009## (in Formula (12) and Formula (13), A.sub.4 represents
a straight chain, branched or cyclic alkylene group having 1 to 20
carbon atom(s) which may contain an ether bond or an ester
bond).
In the process for the production of the present invention, a
matrix polymer made of a linear polymer is mixed with a
highly-branched polymer having hydrophilic functional groups at the
molecular ends to be used. The linear polymer and the
highly-branched polymer having hydrophilic functional groups at the
molecular ends to be used are preferably those having chemical
structures of the constituting units which are the same as or
similar to each other. For example, when the hyperbranched polymer
represented by Formula (1) is used, polystyrene, an AS resin, an
ABS resin, an MS resin, an acrylic resin and a methacrylic resin
can be preferably used.
In addition, the process of the present invention can also be
applied even when both types of polymers are not necessarily in the
above-described relationship. In other words, by using a system in
which an apparent phase-separation structure is not formed when the
linear polymer is mixed with the highly-branched polymer having
hydrophilic functional groups at the molecular ends, the process of
the present invention can be applied to any system.
The amount of the highly-branched polymer having hydrophilic
functional groups at the molecular ends to be mixed with the matrix
polymer is generally 25% by mass, preferably 15% by mass, more
preferably 10% by mass as the maximum mixed amount of the
highly-branched polymer, based on the mass of the matrix polymer.
In addition, the minimum mixed amount is 0.1% by mass, preferably
0.5% by mass, more preferably 1% by mass.
When the amount is within the above range of the mixed amount, a
state in which the hydrophilic functional groups at the molecular
ends of the highly-branched polymer are distributed in the
outermost surface of the polymer structure at an enhanced density
can be effectively formed.
Here, in connection with the description of the present invention,
"outermost surface" means the most outer surface of the polymer
structure and means, for example an interface between the polymer
structure and a gas (usually air) or a liquid (water and/or
hydrophilic solvents etc.). The state in which hydrophilic
functional groups at the molecular ends that the highly-branched
polymer has are distributed in the outermost surface of the polymer
structure at an enhanced density means that the hydrophilic
functional groups at the molecular ends of the highly-branched
polymer component is at a detectable level when the polymer
structure is subjected to a surface analysis by an X-ray
photoelectronic spectrometry (XPS). When the highly-branched
polymer having a dithiocarbamate group as a hydrophilic functional
group is concentrated on the surface and/or the interface of the
polymer structure at a density enhanced to a detectable level by
the XPS and the dithiocarbamate group is distributed in the
outermost surface of the polymer structure, the dithiocarbamate
group can effectively act as a photopolymerization initiator, so
that vinyl polymer chains can be grafted to the dithiocarbamate
group positioned in the outermost surface of the polymer structure
at an enhanced density.
There is described a step (hereinafter, abbreviated as "a first
step") of mixing and unifying a matrix polymer made of a linear
polymer and a highly-branched polymer having hydrophilic functional
groups at the molecular ends to form a structure containing the
matrix polymer and the highly-branched polymer in the process for
the production of the present invention.
Examples of the method for the first step include: a method of
directly melt blending both polymers; a method of dissolving both
polymers in a solvent to homogeneously mix both polymers and
distilling-off the solvent; and a method of polymerizing a linear
polymer acting as a matrix in the presence of the highly-branched
polymer having hydrophilic functional groups at the molecular ends,
but are not limited thereto. The solvent used in the case of using
a solvent is not particularly limited so long as it is a solvent
capable of dissolving both polymers. Examples of the solvent
include: aromatic hydrocarbons such as benzene, toluene, xylene and
ethylbenzene; ether compounds such as tetrahydrofuran and diethyl
ether; ketone compounds such as acetone, methyl ethyl ketone,
methyl isobutyl ketone and cyclohexanone; and aliphatic
hydrocarbons such as n-heptane, n-hexane and cyclohexane. These
solvents may be used individually or in combination of two or more
types thereof.
Next, there is described a step (hereinafter, abbreviated as "a
second step") of subjecting the structure containing the matrix
polymer and the highly-branched polymer to either immersion in
water and/or a hydrophilic solvent or exposure to an atmosphere of
vapor of water and/or a hydrophilic solvent at a temperature
falling within the range of a temperature lower than the glass
transition temperature of the matrix polymer by 30.degree. C. to
the decomposition temperature of the matrix polymer.
The second step can be performed at a temperature falling within
the range of a temperature lower than the glass transition
temperature of the matrix polymer by 30.degree. C. to the
decomposition temperature of the matrix polymer.
The specific temperature range depends on the type of the matrix
polymer, however, it is preferably 0 to 200.degree. C., more
preferably 50 to 150.degree. C.
As the hydrophilic solvent used in the second step, water and/or a
hydrophilic solvent can be used, however, the hydrophilic solvent
may be any solvent so long as it is a solvent miscible with water.
Examples of the hydrophilic solvent include: alcohols such as
methanol, ethanol, isopropanol and propanol; ethers such as
dioxane, tetrahydrofuran and 1,2-dimethoxyethane; acetone;
dimethylformamide; and dimethyl sulfoxide.
The time for immersion and exposure in the second step is 0.001 to
100 hours, preferably 0.1 to 50 hours.
Here, the second step can be accordingly performed within the range
in which the polymer structure is not dissolved and a crack or the
like is not caused.
Even only by the first step, the highly-branched polymer having
hydrophilic functional groups at the molecular ends can be
concentrated on the surface of the polymer structure to some
extent, however, it is impossible to concentrate the
highly-branched polymer at a density enhanced to a level detectable
by the XPS.
According to the process for the production of the present
invention, a polymer structure can be obtained, in which in the
outermost surface of the polymer structure containing a matrix
polymer made of a linear polymer and a highly-branched polymer
having hydrophilic functional groups at the molecular ends, the
hydrophilic functional groups at the molecular ends of the
highly-branched polymer is distributed at a density enhanced to a
level detectable by the XPS.
By the process for the production of the present invention, it is
possible to distribute hydrophilic functional groups at the
molecular ends of the highly-branched polymer in the outermost
surface of the polymer structure at an enhanced density extremely
efficiently.
Accordingly, the present invention provides a polymer structure in
which hydrophilic functional groups at the molecular ends of the
highly-branched polymer are distributed in the outermost surface of
the polymer structure at an enhanced density.
The polymer structure of the present invention is not particularly
limited in the form thereof and can take various forms such as a
film, a membrane, a sheet, a sphere, a granular matter, a fiber and
a molded form.
Further, the present invention provides a grafted polymer structure
in which vinyl polymer chains are graft-polymerized to hydrophilic
functional groups positioned in the outermost surface of the
polymer structure.
In a polymer structure containing a highly-branched polymer having
a dithiocarbamate group at the molecular ends acting as a
photopolymerization initiator as the hydrophilic functional group,
hydrophilic functional groups at the molecular ends of the
highly-branched polymer are distributed in the outermost surface of
the polymer structure at an enhanced density, so that by performing
a living radical polymerization on the surface, vinyl polymer
chains can be grafted to the dithiocarbamate group.
Examples of the monomers forming the vinyl polymer chains to be
grafted include monomers having at least one graft-polymerizable
vinyl group. Specific examples of the monomers include styrenes,
vinylbiphenyls, vinylnaphthalenes, vinylanthracenes, acrylic acids,
methacrylic acids, acrylic esters, methacrylic esters, acrylamides,
methacrylamides, vinylpyrrolidones, acrylonitriles, maleic acids,
maleimides, divinyl compounds and trivinyl compounds.
The surface grafting by a living radical polymerization can be
performed by a publicly-known polymerization method such as a
method for performing the polymerization in a bulk state in a
monomer forming the vinyl polymer chain and a method for performing
the polymerization in a solution state using water or an organic
solvent.
The surface grafting by a living radical polymerization can be
performed by heating or irradiating light such as a UV ray and is
preferably performed by irradiating light such as a UV ray. In the
living radical polymerization, it is necessary to thoroughly remove
oxygen in the reaction system before the initiation of the
polymerization and it is preferred to purge the inside of the
system with an inert gas such as nitrogen and argon. Examples of
the polymerization time include 0.1 to 100 hours, 1 to 50 hours and
3 to 30 hours. The polymerization temperature is not particularly
limited, however, examples of the polymerization temperature
include 0 to 200.degree. C., 10 to 150.degree. C. and 20 to
100.degree. C.
During the living radical polymerization, for controlling the
molecular mass or the distribution of the molecular mass, a chain
transfer agent such as mercaptans and sulfides and a sulfide
compound such as tetraethylthiuram disulfide can be used. Further,
if desired, an antioxidant such as hindered phenols, a UV ray
absorbing agent such as benzotriazoles and a polymerization
inhibitor such as 4-tert-butyl catechol, hydroquinone, nitrophenol,
nitrocresol, picric acid, phenothiazine and dithiobenzoyl disulfide
can be used.
By the above method, a grafted polymer structure in which vinyl
polymer chains are graft-polymerized to the outermost surface of
the polymer structure can be obtained. In addition, when the graft
polymerization is performed by irradiating light, a patterning of
the graft-polymerized part is possible by using an appropriate
mask.
EXAMPLES
The characteristics of the present invention will be further
described in more detail referring to examples, which should not be
construed as limiting the scope of the present invention.
Here, in the following description, for the X-ray photoelectron
spectroscopy (XPS) measurement and the ultra violet light (UV)
irradiation, the following apparatuses were used. (1) X-ray
photoelectron spectroscopy (XPS) XPS, PHI5800 ESCA system
(manufactured by Physical Electronics, Co., Ltd.) (2) Ultra violet
light (UV) irradiation Mercury-Xenon lamp L8251 (manufactured by
Hamamatsu Photonics K.K.) Color filter UV-33 (manufactured by
Toshiba Glass Co. Ltd.) (3) Film thickness measurement Ellipsometry
apparatus M-150 (manufactured by JASCO Co., Ltd.)
Example 1
A hyperbranched polymer represented by Formula (14):
##STR00010## having dithiocarbamate groups at the molecular ends
(trade name: OPTBEADS HPS; manufactured by Nissan Chemical
Industries, Ltd.; Mn=4,900) and a linear polystyrene (PS)
(manufactured by Sigma-Aldrich Corporation; Mn=1,550,000) were
dissolved in a toluene solution so that the ratio (HPS/PS) is
(HPS/PS)=(5/95 (w/w)).
The obtained solution was applied on a silicon substrate by a spin
coating method and dried to prepare an (HPS/PS) blend film.
Subsequently, the blend film (film thickness: 200 nm) was immersed
in pure water and was subjected to thermal treatment at 358K
(85.degree. C.) for 15 hours while performing an argon bubbling.
The surface aggregation structure of the blend film was evaluated
by an X-ray photoelectron spectroscopy (XPS). The result is shown
in FIG. 1.
For the surface graft polymerization using a dithiocarbamate group
as an initiator, N-isopropylacrylamide (NIPAAm) (manufactured by
Kanto Chemical Co., Inc.) was used as a monomer. The blend film was
immersed in a 10% by mass NIPAAm aqueous solution which had been
subjected to argon bubbling and the film was irradiated with an
ultra violet light (UV) having a wavelength of 365 nm. The
irradiation time and the illuminance were set to 24 hours and 5
mW/cm.sup.2, respectively. The film after the UV irradiation was
thoroughly cleaned using ethanol. The aggregation structure of the
blend film surface both before and after the UV irradiation was
evaluated by the XPS and the film thickness was evaluated by the
depth analysis of the XPS measurement and by the ellipsometry
measurement. The film thickness was found to be about 10 nm.
FIG. 1 is an XPS N.sub.1s spectrum for the blend film before and
after the thermal treatment in water. From the finding that the
strength of N.sub.1s ascribed to a dithiocarbamate groups at the
molecular ends of HPS increases, it is apparent that by subjecting
the blend film to thermal treatment in water, HPS is concentrated
on the outermost surface of the (HPS/PS) blend film.
FIG. 2 is an XPS C.sub.1s spectrum before and after the graft
polymerization. From the finding that a peak of a carbonyl carbon
ascribed to NIPAAm was observed at around 288 eV, it can be
concluded that a grafted layer of the polymer formed from NIPAAm
was formed on the PS matrix. The thickness of the grafted layer
could be arbitrarily controlled by varying the polymerization
conditions. The wettability of the surface was largely
enhanced.
Example 2
The (HPS/PS) blend film prepared in Example 1 was subjected to the
thermal treatment according to substantially the same conditions
and procedures as those in Example 1. Subsequently, a graft
polymerization with NIPAAm was performed relative to the thermally
treated (HPS/PS) blend film at the same temperature of 20.degree.
C. as that in Example 1 under such conditions as an illuminance of
2 mW/cm.sup.2 and an irradiation time of 2 hours, and the grafted
polymer layer formed from NIPAAm was formed on the PS matrix.
Example 3
The (HPS/PS) blend film prepared in Example 1 was subjected to the
thermal treatment according to substantially the same conditions
and procedures as those in Example 1. Subsequently, a graft
polymerization with NIPAAm was performed relative to the thermally
treated (HPS/PS) blend film at the same temperature of 20.degree.
C. as that in Example 1 under such conditions as an illuminance of
5 mW/cm.sup.2 and an irradiation time of 2 hours, and the grafted
polymer layer formed from NIPAAm was formed on the PS matrix.
Example 4
The (HPS/PS) blend film prepared in Example 1 was subjected to the
thermal treatment according to substantially the same conditions
and procedures as those in Example 1. Subsequently, a graft
polymerization with NIPAAm was performed relative to the thermally
treated (HPS/PS) blend film at the same temperature of 20.degree.
C. as that in Example 1 under such conditions as an illuminance of
7 mW/cm.sup.2 and an irradiation time of 24 hours, and the grafted
polymer layer formed from NIPAAm was formed on the PS matrix.
Example 5
The (HPS/PS) blend film prepared in Example 1 was subjected to the
thermal treatment according to substantially the same conditions
and procedures as those in Example 1. Subsequently, a graft
polymerization with NIPAAm was performed relative to the thermally
treated (HPS/PS) blend film at the same temperature of 20.degree.
C. as that in Example 1 under such conditions as an illuminance of
15 mW/cm.sup.2 and an irradiation time of 3 hours, and the grafted
polymer layer formed from NIPAAm was formed on the PS matrix.
Example 6
The (HPS/PS) blend film prepared in Example 1 was subjected to the
thermal treatment according to substantially the same conditions
and procedures as those in Example 1. Subsequently, a graft
polymerization with NIPAAm was performed relative to the thermally
treated (HPS/PS) blend film at the same temperature of 20.degree.
C. as that in Example 1 under such conditions as an illuminance of
15 mW/cm.sup.2 and an irradiation time of 24 hours, and the grafted
polymer layer formed from NIPAAm was formed on the PS matrix.
Example 7
The (HPS/PS) blend film prepared in Example 1 was subjected to the
thermal treatment according to substantially the same conditions
and procedures as those in Example 1. Subsequently, a graft
polymerization with NIPAAm was performed relative to the thermally
treated (HPS/PS) blend film at the same temperature of 20.degree.
C. as that in Example 1 under such conditions as an illuminance of
20 mW/cm.sup.2 and an irradiation time of 24 hours, and the grafted
polymer layer formed from NIPAAm was formed on the PS matrix.
Example 8
The (HPS/PS) blend film prepared in Example 1 was subjected to the
thermal treatment according to substantially the same conditions
and procedures as those in Example 1. Subsequently, a graft
polymerization with NIPAAm was performed relative to the thermally
treated (HPS/PS) blend film at the same temperature of 20.degree.
C. as that in Example 1 under such conditions as an illuminance of
25 mW/cm.sup.2 and an irradiation time of 6 hours, and the grafted
polymer layer formed from NIPAAm was formed on the PS matrix.
Example 9
The (HPS/PS) blend film prepared in Example 1 was subjected to the
thermal treatment according to substantially the same conditions
and procedures as those in Example 1. Subsequently, a graft
polymerization with NIPAAm was performed relative to the thermally
treated (HPS/PS) blend film under such conditions as a temperature
of 30.degree. C., an illuminance of 15 mW/cm.sup.2 and an
irradiation time of 6 hours, and the grafted polymer layer formed
from NIPAAm was formed on the PS matrix.
Example 10
The (HPS/PS) blend film prepared in Example 1 was subjected to the
thermal treatment according to substantially the same conditions
and procedures as those in Example 1. Subsequently, a graft
polymerization with NIPAAm was performed relative to the thermally
treated (HPS/PS) blend film under such conditions as a temperature
of 30.degree. C., an illuminance of 15 mW/cm.sup.2 and an
irradiation time of 12 hours, and the grafted polymer layer formed
from NIPAAm was formed on the PS matrix.
Example 11
The (HPS/PS) blend film prepared in Example 1 was subjected to the
thermal treatment according to substantially the same conditions
and procedures as those in Example 1. Subsequently, a graft
polymerization with NIPAAm was performed relative to the thermally
treated (HPS/PS) blend film under such conditions as a temperature
of 30.degree. C., an illuminance of 15 mW/cm.sup.2 and an
irradiation time of 40 hours, and the grafted polymer layer formed
from NIPAAm was formed on the PS matrix.
Example 12
The (HPS/PS) blend film prepared in Example 1 was subjected to the
thermal treatment according to substantially the same conditions
and procedures as those in Example 1. Subsequently, a graft
polymerization with NIPAAm was performed relative to the thermally
treated (HPS/PS) blend film under such conditions as a temperature
of 50.degree. C., an illuminance of 15 mW/cm.sup.2 and an
irradiation time of 1 hour, and the grafted polymer layer formed
from NIPAAm was formed on the PS matrix.
Example 13
The (HPS/PS) blend film prepared in Example 1 was subjected to the
thermal treatment according to substantially the same conditions
and procedures as those in Example 1. Subsequently, a graft
polymerization with NIPAAm was performed relative to the thermally
treated (HPS/PS) blend film under such conditions as a temperature
of 50.degree. C., an illuminance of 15 mW/cm.sup.2 and an
irradiation time of 3 hours, and the grafted polymer layer formed
from NIPAAm was formed on the PS matrix.
Example 14
The (HPS/PS) blend film prepared in Example 1 was subjected to the
thermal treatment according to substantially the same conditions
and procedures as those in Example 1. Subsequently, a graft
polymerization with NIPAAm was performed relative to the thermally
treated (HPS/PS) blend film under such conditions as a temperature
of 50.degree. C., an illuminance of 15 mW/cm.sup.2 and an
irradiation time of 6 hours, and the grafted polymer layer formed
from NIPAAm was formed on the PS matrix.
Example 15
The (HPS/PS) blend film prepared in substantially the same manner
as in Example 1 was subjected to thermal treatment in an
water-vapor atmosphere at 373K (100.degree. C.) for 24 hours. The
polymerization with NIPAAm was performed in substantially the same
manner as in Example 1, and the grafted polymer layer formed from
NIPAAm could be formed on the PS matrix.
Comparative Example 1
The (HPS/PS) blend film prepared in substantially the same manner
as in Example 1 was not subjected to thermal treatment, and in this
case, the surface fraction of the dithiocarbamate groups of the
molecular ends of HPS was extremely low. A curve 1 in FIG. 3 shows
an XPS N.sub.1s spectrum of the freshly-formed film. A finding that
there was observed no apparent peak indicates that the surface
fraction of the dithiocarbamate groups of the molecular ends of HPS
was extremely low.
Although, the polymerization was performed using this film in
substantially the same manner as in Example 1, the formation of the
grafted layer could not be confirmed.
Comparative Example 2
The (HPS/PS) blend film prepared in substantially the same manner
as in Example 1 was subjected to thermal treatment in vacuum at
423K (150.degree. C.) for 24 hours. A curve 2 in FIG. 3 shows an
XPS N.sub.1s spectrum of the film. A finding that there was
observed no N.sub.1s signal at all indicates that the surface
fraction of the dithiocarbamate groups of the molecular ends of HPS
was extremely low.
Although, the polymerization was performed using this film in
substantially the same manner as in Example 1, the formation of the
grafted layer could not be confirmed.
Industrial Applicability
The present invention can contribute to the development of various
functional polymers utilized in various industrial fields as an
invention providing a simple and inexpensive technology having
versatility and capable of modifying the surface of a polymer
structure.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an XPS N.sub.1s spectrum for the blend film before and
after thermal treatment in water in Example 1. Numeral 1 in the
figure shows a spectrum before the thermal treatment in water and
numeral 2 in the figure shows a spectrum after the thermal
treatment in water.
FIG. 2 is an XPS C.sub.1s spectrum before and after graft
polymerization in Example 1. Numeral 1 in the figure shows a
spectrum before the graft polymerization and numeral 2 in the
figure shows a spectrum after the graft polymerization.
FIG. 3 is an XPS N.sub.1s spectrum for the blend film before and
after thermal treatment in water in Example 1, Comparative Examples
1 and 2. Numeral 1 and 2 in the figure show spectra in Comparative
Example 1 and Comparative Example 2, respectively, and numeral 3 in
the figure shows a spectrum after the thermal treatment in water in
Example 1.
* * * * *